The World Health Organization is pressing Russia for additional information about the unexplained death of an employee at a Siberian plague research institute and reports that a second worker may also have developed pneumonia of undetermined cause, deepening international scrutiny of an incident that U.S. health officials continue to monitor.
The development comes one day after V.I. Consortium reported that the U.S. Centers for Disease Control and Prevention was monitoring the death of a 28-year-old employee at the Irkutsk Anti-Plague Research Institute while saying there was no indication of a broader threat to the United States.
What has changed since then is the level of detail WHO says it still needs from Russian authorities.
WHO Director of Epidemic and Pandemic Management Maria Van Kerkhove said Wednesday that the agency does not know what organism caused the illness that killed the laboratory worker, Darya Shipilova, on October 2.
The agency has asked Russia to clarify the cause of her severe pneumonia, identify the pathogen that led authorities to impose significant public-health precautions and address media reports that another employee of the institute developed pneumonia of undetermined origin.
WHO Director-General Tedros Adhanom Ghebreyesus said timely and transparent information sharing under international health rules is necessary to resolve conflicting reports and accurately assess any potential public-health danger.
The report concerning a second employee remains unconfirmed.
Reuters reported Wednesday that it was unable to locate evidence supporting some circulating claims that a second person had died of plague. WHO's request refers more narrowly to reports of a second institute employee suffering from pneumonia of undetermined cause.
Russian officials continue to strongly reject suggestions that a plague outbreak is underway.
Russia's federal health regulator, Rospotrebnadzor, said Wednesday that authorities had concluded there was no risk of an epidemic and were winding down precautionary measures imposed following Shipilova's death.
According to the agency, nearly 5,000 laboratory tests conducted as part of the investigation found no dangerous pathogens. Russian officials said no plague was detected among people who had contact with Shipilova, and 90 percent of those initially quarantined had been released by Wednesday.
Approximately 200 people had initially been placed under quarantine or medical observation following the worker's illness.
Russian authorities also said Shipilova had been vaccinated against the dangerous pathogens she handled professionally. They have not, however, publicly established what caused the severe pneumonia that resulted in her death.
That unresolved question is now at the center of WHO's inquiry.
Russia previously informed WHO that no plague cases had recently been registered in the Irkutsk region. Authorities said contact tracing, laboratory testing, medical monitoring and other preventive measures were undertaken after Shipilova became ill.
Tests among contacts identified two cases of Covid-19 and two rhinovirus infections, but Russian officials said no other infectious pathogens were found.
Kremlin spokesman Dmitry Peskov said Wednesday that Russia had provided WHO with information according to established procedures and accused some media outlets of circulating false information about the incident.
WHO has nevertheless said it requires additional information to determine precisely what happened.
Van Kerkhove said Wednesday that the agency still does not know the “causative agent” responsible for Shipilova's illness.
The Irkutsk Anti-Plague Research Institute studies plague and other dangerous infectious agents in Siberia, a region where the plague bacterium can occur naturally in wildlife.
Initial reports surrounding Shipilova's death raised concerns that she may have suffered pneumonic plague following an accidental laboratory exposure. Russian authorities have not substantiated those reports and have said inspections found no emergency involving pathogenic microorganisms at the institute.
WHO has not confirmed that Shipilova had plague.
The international agency continues to characterize the public-health risk as limited based on the information currently available. Its earlier assessment placed the risk at moderate-to-low within Irkutsk, low across Russia and very low internationally.
The CDC has similarly said it sees no indication of a broader threat to the United States while continuing to follow developments with other U.S. government agencies.
As V.I. Consortium reported Tuesday, pneumonic plague is the lung-based and most dangerous form of infection caused by Yersinia pestis. Unlike the more common bubonic form, pneumonic plague can spread from an infected person through respiratory particles during sufficiently close contact.
It can progress quickly but is treatable with antibiotics when recognized early.
WHO says the incubation period for pneumonic plague can be as short as 24 hours. Without treatment, the disease can be fatal, while patients who are identified and treated promptly have a much better chance of recovery.
The CDC similarly advises healthcare providers not to delay antibiotic treatment while awaiting laboratory confirmation when plague is strongly suspected.
For now, there is no confirmed plague outbreak in Russia, no confirmed second plague case and no indication of a threat to the U.S. Virgin Islands or the wider United States.
